埋地储罐清洗无组织排放油气冷凝法净化工艺模拟分析

Simulated analysis of condensation process for oil vapor fugitive emission from underground oil storage tank cleaning step

针对净化埋地储罐清洗无组织排放油气水蒸气和HC浓度高的特点,采用Aspen软件的Flash 2模拟了单组分和多组分有机废气的冷凝过程,研究了水蒸气含量、冷凝温度、有机物结构等因素对液相回收率的影响,并模拟计算了3级冷凝工艺的净化效率。结果表明:温度低于0℃时,气体中水蒸气浓度不影响液相水的冷凝效率;对于C_6H_(14)废气,冷凝温度和同分异构是影响有机组分回收效率的重要因素,正己烷的全回收温度(T_(99.5%))比2,2-二甲基丁烷高15℃,模拟结果计算正己烷的摩尔蒸发焓为34.758 k J·mol^(-1),与理论值接近;当采用温度分别为0、-40和-75℃3级冷凝工艺时,液相HC回收率达到77.2%。

Flash 2 in Aspen software was used to simulate the condensation process to treat the oil vapor from fugitive emission in underground oil storage tank cleaning step in this paper.Due to the characteristic of the higher concentration of water vapor and HC in the oil vapor,the effects of water vapor content,condensation temperature,and organic structure on the recovery efficiency were investigated on the single component or multicomponent organic waste gas,and the purification efficiency of three-stage condensation process was also simulated and calculated.The results showed that when the temperature was lower than 0 ℃,the recovery of liquid water was not affected by water vapor concentration.For C6H（14）-contained waste gas,the condensing temperature and the isomeric structure were the major factors for the recovery efficiency,T99.5%of n-hexane was 15 ℃ higher than that of 2,2-dimethyl-butane.The molar vaporization enthalpy of n-hexane calculated with Aspen results was 34.758 kJ·mol-1,and was close to the theoretical value.When the temperatures of the three-stage condensation process were set as 0,-40 and -75 ℃,the recovery of liquid HC reached 77.2%.